In early February, Google announced that its home security and alarm system Nest Secure would be getting an update. Users, the company said, could now enable its virtual-assistant technology, Google Assistant.

The problem: Nest users didn't know a microphone existed on their security device to begin with.

The existence of a microphone on the Nest Guard, which is the alarm, keypad, and motion-sensor component in the Nest Secure offering, was never disclosed in any of the product material for the device.

On Tuesday, a Google spokesperson told Business Insider the company had made an "error."

"The on-device microphone was never intended to be a secret and should have been listed in the tech specs," the spokesperson said. "That was an error on our part."